7. A quadrilateral has the following vertices:
[tex]\[
\begin{array}{l}
A(0,4) \\
B(8,4) \\
C(4,-8) \\
D(-4,-8)
\end{array}
\][/tex]

If the scale factor is [tex]\(\frac{1}{4}\)[/tex], what is the relationship between the length of side [tex]\(AB\)[/tex] and the length of side [tex]\(A'B'\)[/tex]?



Answer :

To solve the problem of comparing the length of side [tex]\(AB\)[/tex] with its scaled version [tex]\(A'B'\)[/tex], we will proceed with the following steps:

### Step 1: Determine the length of [tex]\(AB\)[/tex]

Given the coordinates of points [tex]\(A\)[/tex] and [tex]\(B\)[/tex]:
- [tex]\(A(0, 4)\)[/tex]
- [tex]\(B(8, 4)\)[/tex]

We use the distance formula to calculate the length of [tex]\(AB\)[/tex]:
[tex]\[ \text{Length of } AB = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \][/tex]
where [tex]\(A = (x_1, y_1)\)[/tex] and [tex]\(B = (x_2, y_2)\)[/tex].

Substituting the coordinates:
[tex]\[ \text{Length of } AB = \sqrt{(8 - 0)^2 + (4 - 4)^2} \][/tex]
[tex]\[ = \sqrt{8^2 + 0^2} \][/tex]
[tex]\[ = \sqrt{64} \][/tex]
[tex]\[ = 8.0 \][/tex]

### Step 2: Determine the length of [tex]\(A'B'\)[/tex]

Given the scale factor [tex]\(\frac{1}{4}\)[/tex], the length of the scaled side [tex]\(A'B'\)[/tex] is:

[tex]\[ \text{Length of } A'B' = \text{Length of } AB \times \frac{1}{4} \][/tex]
[tex]\[ = 8.0 \times \frac{1}{4} \][/tex]
[tex]\[ = 2.0 \][/tex]

### Step 3: Determine the ratio of the lengths

To compare the lengths of [tex]\(AB\)[/tex] and [tex]\(A'B'\)[/tex], we find the ratio of the length of [tex]\(AB\)[/tex] to the length of [tex]\(A'B'\)[/tex]:
[tex]\[ \text{Ratio} = \frac{\text{Length of } AB}{\text{Length of } A'B'} \][/tex]
[tex]\[ = \frac{8.0}{2.0} \][/tex]
[tex]\[ = 4.0 \][/tex]

### Conclusion

The relationship between the length of side [tex]\(AB\)[/tex] and the length of side [tex]\(A'B'\)[/tex] is that the length of [tex]\(A'B'\)[/tex] is exactly one-fourth the length of [tex]\(AB\)[/tex]. The ratio of the length of [tex]\(AB\)[/tex] to the length of [tex]\(A'B'\)[/tex] is [tex]\(4.0\)[/tex].